Answer: D. [tex]\dfrac{-1}{128}[/tex]
Step-by-step explanation:
The given geometric sequence : 1, -1/2, 1/4, -1/8
Here the first term= [tex]a=1[/tex]
Second term =[tex]ar=\dfrac{-1}{2}[/tex], where r is the common ratio.
Therefore, the common ratio of the given sequence = [tex]r=\dfrac{-1}{2}[/tex]
The nth term of the geometric sequence is given by ;-
[tex]ar^{n-1}[/tex]
Now, the 7th term of the geometric sequence is given by :-
[tex](1)(\dfrac{-1}{2})^{8-1}=(\dfrac{-1}{2})^7=\dfrac{-1}{128}[/tex]
